The presented invention is described below with exemplary reference to an aircraft and, more specifically, with exemplary reference to systems and system networks in an aircraft. However, it should already be noted at this point that the presented invention is by no means limited to the application in aircraft, but rather is suitable for use in all types of systems that comprise more or less complex system components and are located in any vehicles, objects, machines or the like.
The peculiarity with respect to aircraft systems can be seen in that many system components are realized in the form of so-called “Line Replacement Units” (LRU) that allow a replacement within a short stopover on the ground of no less than about two hours. In this way, a high level of utilization of the aircraft can be achieved and required maintenance does not necessarily lead to an immediate and prolonged standstill.
In order to simplify maintenance operations, modern commercial aircraft frequently comprise a central maintenance system (also referred to as “Central Maintenance System (CMS)”) that receives maintenance information from systems within the aircraft if faults or failures occur within one or more systems. The function of the central maintenance system consists of providing a maintenance team with maintenance information or maintenance advice. Such maintenance information contains a listing of potential system components that need to be replaced in order to restore a function that can no longer be performed. Ideally, only a single system component to be replaced is specified. In complex systems, however, the system component responsible for a detected fault frequently cannot be directly determined. Accordingly, the maintenance information may also specify several system components to be replaced or possibly an incorrect system component to be replaced. This could lead to an incorrect system component being removed from the aircraft. The removed system component is inspected by a certified technician who may then determine that the removed system component is completely intact and operational. Subsequently, another system component of the aircraft needs to be replaced and inspected. The costs for inspecting the respective system components are very high, particularly with respect to aircraft systems, because repairs or inspections of this type can only be carried out by a competent technician in compliance with all approval regulations. The faultless state of an inspected system component is also referred to as “No Fault Found (NFF)” below.
In known maintenance systems, it is furthermore common practice that the maintenance messages transmitted to a maintenance team can be statically reproduced such that the same system component to be replaced is always suggested when a certain fault is detected. Consequently, the proportion of removed system components with the state NFF (faultless) can be quite high in known maintenance systems, particularly if the respective system is complex and comprises many interacting system components that make it difficult to determine the cause of the fault.
DE 101 53 151 A1 and US 2003 083 794 A1 pertain to a diagnostic system for facilitating the maintenance of a commercial aircraft, wherein at least one sensor device for generating and storing sensor signals is provided at least at one inspection point in order to diagnose faults on high-maintenance aircraft systems, and wherein the sensor signals can be transmitted to a processing unit and the processing unit is functionally connected to a display device that displays the sensor signals and/or the determined diagnostic information.